We have a grown son that does not camp with us anymore and we have two daughters, 10 and 13. We took both of them on their first camping trip when they were 3 months old and since the second daughter arrived, we have had some type of bunkhouse. We had a TT bunkhouse that had 2-twin sized beds and 2-bunk size beds; then we had a fifth wheel with the front bunkhouse. It had 3-bunk sized and a jack-knife sofa.
We would never consider anything that has the kids sleeping in the common area since the teen likes to sleep late and the younger goes to bed early. We camp at least 60 nights each year, usually closer to 100. We camp-host from May through September, and that is a lot of time to be cooped up in a little bitty area if everyone doesn't have a "space".